This invention relates to a document writing apparatus which is operated to input words and sentences to edit a document while simultaneously displaying another document in the same frame.
Recently, many document writing apparatuses including word processors have been developed which are improved in operability by adding a function of enabling the operator to write a document while simultaneously referring to another document previously written. For this kind of conventional document writing apparatus, a method for simultaneously displaying two documents in one frame has been used in which the area of one frame is bisected into left and right or upper and lower sections, an edited main document being displayed in the left or upper section, a sub document read out to be referred to or copied being displayed on the right or lower section.
FIG. 1 is a block diagram of the construction of a conventional document writing apparatus. A component 1 shown in FIG. 1 is a character input means for inputting characters of kana, kanji, English characters, Arabic numerals and the like. An array of input characters is changed by proofreading and/or edited by an editing means 2 while being displayed by a display means 3. Documents thereby formed are stored by a document storage means 4, and each of the documents can be printed by a printing means 5 if necessary.
At the time of document inputting/editing, a portion of a document which has already been prepared and stored by the document storage means 4 may be used in a document presently edited or may be referred to for editing. In such a case, the two documents are displayed in the same frame by using a two-document invoking means 6, and character inputting/editing are performed under this condition to edit the document.
The operation of this conventional apparatus will be described below with reference to FIGS. 2a to 2d, and FIGS. 3a and 3b.
It is assumed here that display means using 24-dot characters, 16-dot characters and 12-dot characters are provided as the display means of this apparatus, and that while a first document shown in FIG. 2a (35 characters .times. 25 lines per page on a B5 sheet) is being edited and displayed in a one-document display state shown in FIG. 2d by using 24-dot characters, the apparatus is instructed to effect two-document display and reads out a second document shown in FIG. 2b (40 characters .times. 35 lines per page on an A4 sheet) by using the two-document invoking means 6. The contents of the two-document display are thereby displayed on the screen as shown in FIG. 3a. In the two-document display state shown in FIG. 3a, each line of the main and sub documents cannot be entirely displayed, and a troublesome operation of scrolling of each document in the direction of line length is required to edit the document.
In the case of a combination of a third document (90 characters .times. 25 lines per page on a B4 sheet) and the first document, the two-document display state is as shown in FIG. 3b, and the extent of scrolling is further increased. In such a case, the operator selects the 16 dot character display means which enables an increase in the number of characters displayed on one line while limiting the reduction in the character size so that each character is easy to read, and which can avoid occurrence of a need for scrolling. The operator also changes the display system and establishes a two-document display state shown in FIG. 5a by selecting the position at which the left and right sections for displaying the two documents are divided so that there is no need to scroll one or both of the two documents. Thereafter, the operator inputs characters and edits the document.
In the conventional document writing apparatus, however, the dot construction of each character and the position at which the frame area is divided for two-document display are fixed with respect to each apparatus, and, to establish a two-document display condition free from occurrence of a need for scrolling one or both of the main and sub documents, it is necessary for the operator to change the display system and the display condition by considering both the formats of the two documents read out and the display means provided in the apparatus.